{"instruction": "You are an expert in named entity recognition. Please extract entities that match the schema definition from the input. Return an empty list if the entity type does not exist. Please respond in the format of a JSON string.", "schema": ["Chemical"], "input": "Results were compared with those from earthworms exposed to cadmium nitrate and selenious acid , as positive controls , and those exposed in untreated soil ( negative control ) ."}
{"Chemical": ["cadmium nitrate", "selenious acid"]}